public class MyCircularQueue2 {
    //使用标记的操作
    public int[] elem;
    public int front;
    public int rear;
    public boolean isFull;
    public MyCircularQueue2(int k) {
        elem = new int[k];
        boolean isFull=false;
    }
    public boolean enQueue(int value) {
        if(isFull()){
            return false;
        }
        elem[rear]=value;
        rear=(rear+1)%elem.length;
        if(rear==front){
            isFull=true;
        }
        return true;
    }
    public boolean deQueue() {
        if(isEmpty()){
            return false;
        }
        front=(front+1)%elem.length;
        isFull=false;
        return true;
    }
    public int Front() {
        if (isEmpty()){
            return -1;
        }
        return elem[front];
    }
    public int Rear() {
        if (isEmpty()){
            return -1;
        }
        int index=rear==0?elem.length-1:rear-1;//不能使用(rear+1)%elem.length这样会使rear的值改变
        return elem[index];
    }
    public boolean isEmpty() {
        return !isFull&&rear==front;
    }
    public boolean isFull() {
        return isFull;
    }
}
